Fix key access for sqlite3.Row on Python 2.7

Fixes #1607

core/main_db.py

@@ -11,11 +11,37 @@ import re
 import sqlite3
 import time
 
-from six import text_type
+from six import text_type, PY2
 
 import core
 from core import logger
 
+if PY2:
+    class Row(sqlite3.Row, object):
+        """
+        Row factory that uses Byte Strings for keys.
+
+        The sqlite3.Row in Python 2 does not support unicode keys.
+        This overrides __getitem__ to attempt to encode the key to bytes first.
+        """
+
+        def __getitem__(self, item):
+            """
+            Get an item from the row by index or key.
+
+            :param item: Index or Key of item to return.
+            :return: An item from the sqlite3.Row.
+            """
+            try:
+                # sqlite3.Row column names should be Bytes in Python 2
+                item = item.encode()
+            except AttributeError:
+                pass  # assume item is a numeric index
+
+            return super(Row, self).__getitem__(item)
+else:
+    from sqlite3 import Row
+
 
 def db_filename(filename='nzbtomedia.db', suffix=None):
     """
@@ -37,7 +63,7 @@ class DBConnection(object):
 
         self.filename = filename
         self.connection = sqlite3.connect(db_filename(filename), 20)
-        self.connection.row_factory = sqlite3.Row
+        self.connection.row_factory = Row
 
     def check_db_version(self):
         result = None